In a container filling machine of, for example, the kind shown in U.S. Pat. Nos. 3,182,691 and 3,207,189 wherein there are filling heads provided with nozzles which are engaged within or above the open tops of the containers during the filling operation, it is customary as part of the operation to clear the interior of the nozzle after it is withdrawn from the container or, alternately, the container has been lowered away from the nozzle by projecting a blast of air through the nozzle. This is provided for by positioning an air pipe within the nozzle to which air is supplied under pressure so as to blow air through the lower end of the nozzle. It has been found that for some filling operations, the product adheres not only to the interior of the nozzle, but also to the exterior surface of the nozzle. If the product is viscous, it tends to string off the nozzle and contaminate the container and threads prior to capping.
Because the outside diameter of the filling nozzle and the inside diameter of the container neck finish provided minimum clearance for the venting of the air in the container, while filling, any buildup of product on the outside of the liquid filling nozzle tended to restrict the air vent, thus producing a back pressure which prematurely shut off the filling process producing a slack filled container.
It is the purpose of this invention to provide for removing the product from the exterior surface of the nozzle during a period when the nozzle is withdrawn from the container and/or the container is withdrawn from the nozzle to clear the exterior surface of the nozzle. If the filling machine is of the rotary type wherein there is means for loading empty containers into the machine for filling and means for discharging filled containers from the machine after filling, the means for clearing the exterior surface of the nozzles are desirably brought into operation during the interval that each filling head is traveling from the place of discharge to the place of loading.